v3.26.1
Cover - USD ($)
 12 Months Ended
Mar. 31, 2026
Jun. 22, 2026
Sep. 30, 2025
Cover [Abstract]      
Document Type 10-K    
Document Annual Report true    
Document Transition Report false    
Amendment Flag false    
Document Period End Date Mar. 31, 2026    
Document Fiscal Year Focus 2026    
Document Fiscal Period Focus FY    
Current Fiscal Year End Date --03-31    
Entity Registrant Name 21Shares Polkadot ETF    
Entity Central Index Key 0002054247    
Entity File Number 001-43181    
Entity Tax Identification Number 33-6490872    
Entity Incorporation, State or Country Code DE    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Public Float     $ 0
ICFR Auditor Attestation Flag false    
Document Financial Statement Error Correction [Flag] false    
Entity Shell Company false    
Entity Filer Category Non-accelerated Filer    
Entity Small Business true    
Entity Emerging Growth Company true    
Entity Ex Transition Period false    
Entity Address, Address Line One 158 W. 27th Street    
Entity Address, City or Town New York    
Entity Address, Postal Zip Code 10001    
Entity Address, State or Province NY    
City Area Code (646)    
Local Phone Number 370-6016    
Title of 12(b) Security Shares of Beneficial Interest of 21Shares Polkadot ETF    
Trading Symbol TDOT    
Security Exchange Name NASDAQ    
Entity Common Stock, Shares Outstanding   750,000  
Documents Incorporated by Reference [Text Block] None.